Diaphragm for pump



March 15, 19 w. w. TAYLOR 2,928,426

DIAPHRAGM FOR PUMP Filed June 27. 1952 F ngl s lac INVENTOR. Wei/fer W.721y/or ATTORNEY United States Patent DIAPHRAGM FOR PUMP Walter W.Taylor, Oakland, Calif., assignor to Malsbary Manufacturing Company,Oakland, Calif., a corporation of California Application June 27, 1952,Serial No. 295,906

4 Claims. (Cl. 137-788) The invention relates to improvements in adiaphragm pump, and its principal object is to provide certainimprovements in the diaphragm and in the diaphragm assembly to renderthe operation of the pump more efficient and to extend the life of thediaphragm.

In diaphragm pumps, as used heretofore, the diaphragm is usually made inthe form of a heavy disc constructed of alternate layers of rubber andfabric and having parallel end faces throughout the extent thereof.

The rim of the diaphragm is clamped between fixed rings forming part ofthe pump housing, and the free portion of the diaphragm is reciprocatedby means of a drive plate bearing on one side of the diaphragm andclamped upon the latter by means of a central bolt. The head of the boltbears upon a washer disposed on the other side of the diaphragm and thedriving plate is substantially larger than the washer and extendscircumferentially to within close proximity of the anchoring rings.

As the drive plate is reciprocated, by any suitable source of power, andtransmits the reciprocations to the diaphragm for pumping action, themain water on the diaphragm takes place along the rim thereof, that is,just inside the anchoring rings. This is due to the fact that thediaphragm, being very heavy and reinforced by the fabric, and of uniformthickness, flexes very little in its main portion, in response to theadvance of the drive plate, the main part of the flexing being donealong the rim just inside the anchoring rings.

The rim section thus acts in the nature of a well-defined hinge, takessubstantially all the bending stresses and, as a consequence, is subjectto'heavy wear, whereby the life of the diaphragm is seriously shortened.

As a matter of fact, when a diaphragm of this character is removed fordiscarding, there is a clearly defined ring just inside the anchoringrings where the material is completely worn out, while the remainder ofthe diaphragm is still in good condition.

In order to ameliorate this condition it has been proposed, heretofore,to form the driving plate with a convex driving face, to cause thedriving face to engage the diaphragm over progressively spreading areas,and to spread the bending stresses over a wider area. But, in view ofthe construction of the diaphragm hereinabove described, this is only apartial solution of the problem, since the breaking down of thediaphragm material still occurs along the rim.

In the present invention, it is proposed to remedy the situation byproviding a diaphragm of novel construction which allows the bendingstresses to be distributed over a wide area and eliminates the definitehinge efiect hereinabove referred to.

Further objects and advantages of my invention will be disclosed as thespecification continues, and the new and novel features of my diaphragmpump will be fully defined in the claims forming part of thisapplication. The preferred form of my invention is illustrated in theaccompanying drawing, in which:

Figure 1 shows a fragmentary axial section through a 2,928,426 PatentedMar. 15, 1960- i ce 2 diaphragm pump disclosing my diaphragm and itsmounting means, and

Figure 2, a plan view of my diaphragm.

While I have shown only the preferred form of my invention, it should beunderstood that variouschanges or modifications may be made within thescope of the claims attached hereto, without departing from the spiritof the invention.

Referring to the drawing in detail, my diaphragm 1 is preferably made ofall rubber to increase the flexibility thereof. It is made in the formof a disc having a central bolt hole 2 with a metallic reinforcing ring3 therein, and is circumferentially confined by a second reinforcingring 4. The disc is, in its original state, somewhat thicker than thewidth of the rings to allow of the clamping action hereinafter referredto.

One .side 5 of the disc, which may be referred to as the driving face,is perfectly flat, While the other side 6 has a flat rim section 7, aflat hub section Sand an annular concave groove'9 between the twosections.

While I do not wish to confine myself to any exact dimensions, I mightsay, that in the diaphragm actually used and recently tested by me, therim section, the grooved or intermediate section and thehub section areabout equal in width along a radial line, as shown in the drawing, andthat the groove extends into the disc material to a depth approximatelyequal to one-third of the thickness of the disc. The, latter may have adiameter of approximately five and one-half inches, and a thickness ofapproximately one-half inch.

The rim section is formed with an annular series of bolt holes 10.

My diaphragm may be mounted in a pump substantially as shown in Figurel. The pump may be of any suitable construction, and is here shown ascomprising a housing 11 having two ring members 12 and 13 clamped uponthe rim of the diaphragm by means of a series of bolts 14 passingthrough the bolt holes 10 in the diaphragm.

The housing is constructed to form a pump chamber 15 on one side of thediaphragm, with suitable intake and discharge valves 16 and 17 for thechamber, the latter facing the grooved side of the disc.

A drive plate 18 is mounted centrally upon the fiat side of thediaphragm and is secured to the latter by means of a bolt 19 extendingthrough the ring 3 in the hole 2. The head of the bolt bears on a washeror confining ring 20 interposed between the head and the flat hubsection 8 of the disc, and the end of the bolt is threaded into a nut21, which latter has a ring 22 mounted thereon operable by an eccentric,not shown, to cause the drive plate to reciprocate.

The drive plate 18 has a driving face which may be substantially fiat inits inner portion commensurate with the size of the washer, but which isconvex in its outer portion, as at 23, beyond the circumference of thewasher. The diameter of the drive plate is slightly less than the innerdiameter of the anchoring rings 12 and 13.

My construction brings the concaved portion of the diaphragm discsubstantially opposite the convex portion of the drive plate.

In operation, as the drive plate 18 advances, it progressively contactsthe disc in widening circles, urging first the central section and thenthe grooved or concaved section of thedisc outwardly. In the meantime,the disc, growing progressively thinner, as the contact area widens,offers less and less resistance to bending stresses and flexes ratherfreely throughout the contact area.

This flexing through a wide area more uniformly distributes the bendingstresses in the disc material and does away with the concentration ofthe bending stress along a narrow rim section, particularly in view ofthe fact tli'aftoward'thes'aid section; the disc material grows thickeragain in the present construction.

I have found, by severe tests, that in my construction,

the tendency of the disc to break at the rim portion adjacent'the'anchoring plates, is substantiallyeliminated, and that the life ofthe disc is greatly extended.

I claim: V

1. A pre-formed diaphragm for a diaphragm pump having a drive plate witha driving face flat in its central portion and convex in, its outerportion, the diaphragm being" adapted for securing upon, thedrive plateand having a flat face adjacent the drive plate and having aconcavegroove in itso'ppo'site'face disposed opposite theconve'x portionof the drive plate when the diaphragm is secured upon the latter.

7 21' A pie-formed diaphragm for a diaphragm pump ha'vin'g a drive platewith a'driving face fia t in its central portio'n and convex in itsouter portion, the diaphragm being adapted for' securing upon the driveplate and having a flat face-adjacent the driveplate and having aconcave groove in its opposite face disposed opposite the convex portionof the drive plate when the diaphragm is secured upon the latter, andthe groove being sub stantially commensurate ,with the convex portion.

3'. A pre-formed diaphragm for a diaphragm pump havingta drive platewith a driving face flat in its central portion and convex in its outerportion, the diaphragm beingadapted for securing upon the drive plateand having a flat face adjacent the driveplate and having aconcavegroove in its opposite face disposed opposite the convex portionof the drive plate when the diaphragm is se'c'ured upon thelatter, andthe diaphragm having a rim portion extending beyond the groove andadapted for securing between a pair of fixed anchoring members.

4. A pre-formed diaphragm for a diaphragm pump having a drive plate witha driving face flat in its central portion and convex in its outerportion, the diaphragm I being adapted forsecuring upon the drive .plateand having a flat faceadjacent' the drive plate and having aconcavegro'ove in its opposite face disposed opposite the convers-portion of the drive plate when the diaphragm is secured upon thelatter, the groovebeingsubstantially commensurate with the convexportion, and the diaphragm having a rim portion extending beyond thegroove and adapted for securing between a pair of fixed anchoringmembers.

References Cited in the file of this patent UNITED STATES PATENTS- i r i

